Suture

ABSTRACT

A medical device includes a surgical needle attached to a hollow tubular suture. The suture is constructed of macroporous hollow tubular wall that facilitates and allows tissue integration into the suture core subsequent to introduction to the body, thereby preventing suture pull-through and improving biocompatibility.

CROSS-REFERENCE TO RELATED APPLICATIONS

The priority benefit of U.S. Provisional Patent Application No.61/602,183, filed Feb. 23, 2012, is hereby claimed and the entirecontents thereof are incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure provides sutures with increased surface areaand/or tissue integrative properties and methods of use and manufacturethereof. In particular, provided herein are sutures with cross-sectionprofiles and other structural characteristics that strengthen closure,prevent suture pull-through, and/or resist infection, and methods of usethereof.

BACKGROUND

One of the foundations of surgery is the use of suture to re-apposetissue, i.e., to hold tissue in a desired configuration until it canheal. In principle, suturing constitutes introducing a high tensileforeign construct (looped suture) into separate pieces of tissue inorder to hold those pieces in close proximity until scar formation canoccur, establishing continuity and strength between tissues. Suturesinitially provide the full strength of the repair, but then becomesecondarily reinforcing or redundant as the tissue heals. The time untiltissue healing reaches its maximal strength and is dependent on suturefor approximation, therefore, is a period of marked susceptibility tofailure of the repair due to forces naturally acting to pull the tissuesapart.

Conventional sutures provide a circular or single-point cross-sectionalprofile extended over the length of the suture material. Such a suturehas the great benefit of radial symmetry, which eliminates directionalorientation, allowing the user (e.g., physician, surgeon, medic, etc.)to not have to worry about orienting the suture during use. However, aconsiderable disadvantage of the currently used single-pointcross-section is that it does not effectively distribute force, andactively concentrates force at a geometric point (e.g., the point at theleading edge of the circle) creating a sharp edge in the axialdimension. Under these conditions, the tissue is continuously exposed totension, increasing the likelihood that stress concentration at ageometric point or sharp edge will cut through the tissue.

Indeed, studies of surgical closures, a most prominent example beinghernia repairs, demonstrate that the majority of failures or dehiscencesoccur in the early post-operative period, in the days, weeks, or monthsimmediately following the operation, before full healing can occur.Sutures used to close the abdominal wall have high failure rates asdemonstrated by the outcome of hernia formation. After a standardfirst-time laparotomy, the postoperative hernia occurrence rate isbetween 11-23%. The failure rate of sutures after hernia repair is ashigh as 54%. This is a sizeable and costly clinical problem, withapproximately 90,000 post-operative hernia repairs performed annually inthe United States. Surgical failures have been blamed on poor sutureplacement, suture composition, patient issues such as smoking andobesity, and defects in cellular and extracellular matrices. Clinicalexperience in examining the cause of these surgical failures revealsthat it is not breakage of suture as is commonly thought; in themajority of cases the cause is tearing of the tissue around the suture,or from another perspective, intact stronger suture cutting throughweaker tissue. Mechanical analysis of the suture construct holdingtissue together shows that a fundamental problem with current suturedesign is stress concentration at the suture puncture points through thetissue. That is, as forces act to pull tissues apart, rather than stressbeing more evenly distributed throughout the repair, it is insteadconcentrated at each point where the suture pierces through the tissue.The results are twofold: (1) constant stress at suture puncture pointscauses sliding of tissue around suture and enlargement of the holes,leading to loosening of the repair and an impairment of wound healing,and (2) at every puncture point where the stress concentration exceedsthe mechanical strength of the tissue, the suture slices through thetissue causing surgical dehiscence. In addition, high pressure on thetissue created during tightening of the surgical knot can lead to localtissue dysfunction, irritation, inflammation, infection, and in theworst case tissue necrosis. This tissue necrosis found within the sutureloop is one additional factor of eventual surgical failure.

There has been no commercial solution to the aforementioned problemswith conventional sutures. Rather, thinner sutures continue to bepreferred because it is commonly thought that a smaller diameter mayminimize tissue injury. However, the small cross-sectional diameter infact increases the local forces applied to the tissue, therebyincreasing suture pull-through and eventual surgical failure.

One alternative to the conventional suture is disclosed by Calvin H.Frazier in U.S. Pat. No. 4,034,763. The Frazier patent discloses atubular suture manufactured from loosely woven or expanded plasticmaterial that has sufficient microporosity to be penetrated with newlyformed tissue after introduction into the body. The Frazier patent doesnot expressly describe what pore sizes fall within the definition of“microporosity” and moreover it is not very clear as to what tissue“penetration” means. The Frazier patent does, however, state that thesuture promotes the formation of ligamentous tissue for initiallysupplementing and then ultimately replacing the suture's structure andfunction. Furthermore, the Frazier patent describes that the suture isformed from Dacron or polytetrafluoroethylene (i.e., Teflon®), which areboth commonly used as vascular grafts. From this disclosure, a personhaving ordinary skill in the art would understand that the suturedisclosed in the Frazier patent would have pore sizes similar to thosefound in vascular grafts constructed from Dacron or Teflon®. It is wellunderstood that vascular grafts constructed of these materials serve toprovide a generally fluid-tight conduit for accommodating blood flow.Moreover, it is well understood that such materials have a microporositythat enables textured fibrous scar tissue formation adjacent to thegraft wall such that the graft itself becomes encapsulated in that scartissue. Tissue does not grow through the graft wall, but rather, growsabout the graft wall in a textured manner. Enabling tissue in-growththrough the wall of a vascular graft would be counterintuitive becausevascular grafts are designed to carry blood; thus, porosity large enoughto actually permit either leakage of blood or in-growth of tissue, whichwould restrict or block blood flow, would be counterintuitive and notcontemplated. As such, these vascular grafts, and therefore the smallpore sizes of the microporous suture disclosed in the Frazier patent,operate to discourage and prevent normal neovascularization and tissuein-growth into the suture. Pore sizes less than approximately 200microns are known to be watertight and disfavor neovascularization. See,e.g., Mühl et al., New Objective Measurement to Characterize thePorosity of Textile Implants, Journal of Biomedical Materials ResearchPart B: Applied Biomaterials DOI 10.1002/jbmb, Page 5 (WileyPeriodicals, Inc. 2007). Accordingly, one skilled in the art wouldunderstand that the suture disclosed in the Frazier patent has a poresize that is at least less than approximately 200 microns. Thus, insummary, the Frazier patent seeks to take advantage of thatmicroporosity to encourage the body's natural “foreign body response” ofinflammation and scar tissue formation to create a fibrous scar aboutthe suture.

GENERAL DESCRIPTION

In contrast, the present disclosure is directed to sutures designed todiscourage that “foreign body response” of inflammation and fibrotictissue formation about the suture by utilizing a macroporous structure.The macroporous structure seeks to minimize the foreign body response tothe suture. In direct contrast to the microporous structure, themacroporous structure is optimized to achieve maximal biocompatibilityby permitting neovascularization and local/normal tissue ingrowth intothe suture itself.

In some embodiments, the present disclosure provides surgical suturescomprising a cross-sectional profile lacking radial symmetry. In someembodiments, the surgical suture comprises a ribbon-like geometry. Insome embodiments, the suture is between 0.1 mm and 1 cm wide (e.g. >0.1mm, >0.2 mm, >0.3 mm, >0.4 mm, >0.5 mm, >0.6 mm, >0.7 mm, >0.8 mm, >0.9mm, >1 mm, >2 mm, >3 mm, >4 mm, >5 mm, >6 mm, >7 mm, >8 mm, >9 mm),although other dimensions may be used. In some embodiments, the sutureis about 3.75 mm wide (e.g., 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4mm, 4.5 mm). In some embodiments, the suture comprises a 2Dcross-sectional profile. In some embodiments, the 2D cross-sectionalprofile comprises an ellipse, half ellipse, gibbous, half circle,crescent, concave ribbon, or rectangle; although other shapes may beused. In some embodiments, the suture comprises polyethyleneterephthalate, nylon, polyolefin, polypropylene, silk, polymersp-dioxanone, co-polymer of p-dioxanone, ε-caprolactone, glycolide,L(−)-lactide, D(+)-lactide, meso-lactide, trimethylene carbonate,polydioxanone homopolymer, and combinations thereof, although othermaterials may be used. In some embodiments, the suture comprisespolypropylene. In some embodiments, a suture is sterile, surgical grade,medical grade, etc.

In some embodiments, the present disclosure provides surgical suturescomprising a flexible material containing one or more internal voids(e.g., hollow core, honeycomb, single or multiple lumen, etc.) thatextend the length of the suture. In some embodiments, the surgicalsuture adopts a first cross-sectional profile in the absence of lateralstress, and a second cross-sectional profile in the presence of lateralstress. In some embodiments, the first cross-sectional profile exhibitssubstantial radial symmetry. In some embodiments, the secondcross-sectional profile exhibits partially or wholly collapsedconformation.

In some embodiments, the present disclosure provides surgical suturescomprising material and structure configured to permit tissue in-growthupon placement of the suture into the tissue of a subject. In someembodiments, the material comprises pores that permit tissue in-growth.In some embodiments, the pores comprise macropores (e.g., pores having adiameter >200 μm, >300 μm, >400 μm, >500 μm, >600 μm, >700 μm, >800μm, >900 μm, >1 mm, >2 mm, or more). In some embodiments, the porescomprise micropores (e.g., pores having a diameter <200 μm, <150 μm,<100 μm, <75 μm, <70 μm, <50 μm, <25 μm, <10 μm, <1 μm, <0.5 μm, <0.1μm, or less). In some embodiment, the pores can include a combination ofmacropores and micropores. In some embodiments, the pores may be of anysuitable shape (e.g., circular, diamond, amorphous, etc. In someembodiments, the material comprises a textured surface (e.g., grooves,web, mesh, ribs, barbs, etc.). In some embodiments, the suture comprisesa cross-sectional profile lacking radial symmetry. In some embodiments,the suture comprises a cross-sectional profile lacking substantiallyradial symmetry. In some embodiments, the suture comprises a ribbon-likegeometry. In some embodiments, the suture is between 1 mm and 1 cm wide.In some embodiments, the suture comprises a 2D cross-sectional profile.In some embodiments, the 2D cross-sectional profile comprises anellipse, half ellipse, gibbous, half circle, crescent, concave ribbon,or rectangle. In some embodiments, the suture comprises polypropylene.In some embodiments, a suture is sterile, surgical grade, medical grade,etc.

In some embodiments, the present disclosure provides suturing needlescomprising a distal end and a proximal end, wherein the proximal end isconfigured for attachment to a suture material, wherein the distal endin configured for insertion into tissue, and wherein the needletransitions from a radially symmetric cross-sectional profile (orsubstantially radially symmetric) or so-called triangular “cutting”configurations at the distal end to a cross-sectional profile lackingradial symmetry at the proximal end. In some embodiments, the needleproduces a puncture lacking radial symmetry when inserted through atissue. In some embodiments, the cross-sectional profile lacking radialsymmetry comprises a ribbon-like geometry. In some embodiments, theribbon-like geometry is between 1 mm and 1 cm wide. In some embodiments,the cross-sectional profile lacking radial symmetry comprises a 2Dcross-sectional profile. In some embodiments, the 2D cross-sectionalprofile comprises an ellipse, half ellipse, gibbous, half circle,crescent, concave ribbon, or rectangle. In some embodiments, a suturingneedle is sterile, surgical grade, medical grade, etc.

In some embodiments, the present disclosure comprises a suturing systemcomprising: (a) a suturing needle (e.g., as described above), comprisinga distal end and a proximal end, wherein the proximal end is configuredfor attachment to a suture material, wherein the distal end isconfigured for insertion into tissue, and wherein the needle comprises across-sectional profile lacking radial symmetry at the proximal end ofthe needle; and (b) a surgical suture (e.g., as described above)comprising a cross-sectional profile lacking radial symmetry.

In some embodiments, the present disclosure provides methods of usingany of the above sutures, suturing needles, and/or systems to suture atissue and/or close an opening in a tissue (e.g., epidermal tissue,peritoneum, adipose tissue, cardiac tissue, or any other tissue in needof suturing).

In some embodiments, the present disclosure provides methods of suturingan opening in a tissue comprising: (a) providing a suture with distaland proximal ends, wherein said proximal end is attached to a needle,and wherein said distal end comprises an integrated loop structure; (b)inserting said needle through said tissue adjacent to a first end ofsaid opening; (c) pulling said suture through said tissue until saiddistal end of said suture is adjacent to said tissue; (d) placing saidneedle and said suture through said loop to create a lasso at the distalend of said suture; (e) suturing closed said opening from said first endto a second end; (f) stapling said suture at a second end; and (g)cutting remaining suture material and needle proximal to the staple.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of incision and suture geometry.

FIG. 2 shows a schematic demonstrating the effect of tension between asuture and the surrounding tissue.

FIG. 3 shows finite element analysis of the suture/tissue interface.

FIG. 4 shows finite element analysis demonstrating that increasingsuture size decreases the forces at the suture/tissue interface.

FIG. 5 shows finite element analysis demonstrating that suture shapeimpacts the local forces applied on the tissue by suture.

FIGS. 6 and 7 show graphs demonstrating the relative equivalence of thetensile strength of an O polypropylene suture and 2 mm wide nonradiallysymmetric (ribbon-shaped) suture.

FIG. 8 is an image showing a set-up for a tensometry experimentconducted using traditional 2D sutures and porcine linea alba.

FIG. 9 is an image of the tensometry experiment of FIG. 8, illustratingtension being applied to the porcine linea alba.

FIG. 10 shows an illustration of an exemplary integrated needle andsuture comprising: (1) a sharp needle point, (2) needle body, (3)transition area, (4) flattened profile, (5) porous suture wall, and (6)hollow core.

FIG. 10A is a detailed view of a portion of the porous suture wall ofFIG. 10.

FIG. 11 shows an illustration of an exemplary anchor end comprising acrimped loop: (1) crimpled joint, (2) circular profile.

FIG. 12 shows an illustration of an exemplary anchor end comprising aflattened loop: (1) flattened loop, (2) transition area, (3) circularprofile.

FIG. 13 shows an illustration of an exemplary anchor end comprising aformed loop: (1) formed joint, (2) circular profile.

FIG. 14 shows a schematic demonstrating an altered cross-sectionalprofile upon application of non-axial force to a hollow core suture.

FIG. 15 shows a graph of the effect of suture width on maximum sutureload in ex vivo porcine linea alba.

FIG. 16 shows a graph of the effect of suture width on maximum sutureload in synthetic foam sheeting.

FIGS. 17 and 18 show comparison images of the tissue integration that isachieved with a macroporous suture of the present disclosure versus thefailure suffered with a conventional suture when used to repair a rathernia.

FIG. 19 shows a graph comparing the mean defect area of thirty rathernias repaired in FIGS. 17 and 18 randomized to repair either with amacroporous suture of the present disclosure or with a conventionalsuture. The data analyzes defect size one month after repair.

DETAILED DESCRIPTION

The present disclosure provides a medical suture having a macroporoustubular construct that advantageously promotes neovascularization andnormal tissue in-growth and integration subsequent to introduction intothe body. Additionally, the present disclosure provides various sutureswith increased surface area and/or tissue integrative properties andmethods of use and manufacture thereof. In particular, provided hereinare sutures with cross-section profiles and other structuralcharacteristics that strengthen closure, prevent suture pull-through,and/or resist infection, and methods of use thereof. In someembodiments, sutures are provided that strengthen closure, preventsuture pull-through, and/or resist infection by, for example: (1) havinga cross sectional profile that reduces pressure at suture points, (2)having a structural composition that allows tissue in-growth into thesuture, or both (1) and (2). The present disclosure is not limited byany specific means for achieving the desired ends.

In some embodiments, conventional sutures exhibit a cross-sectionalprofile with radial symmetry or substantially radial symmetry. As usedherein, the term “substantially radial symmetry” refers to a shape(e.g., cross-sectional profile) that approximates radial symmetry. Ashape that has dimensions that are within 10% error of a shapeexhibiting precise radial symmetry is substantially radially symmetric.For example, an oval that is 1.1 mm high and 1.0 mm wide issubstantially radially symmetric. In some embodiments, the presentdisclosure provides sutures that lack radial symmetry and/or substantialradial symmetry.

In some embodiments, sutures are provided comprising cross-sectionshapes (e.g. flat, elliptical, etc.) that reduce tension against thetissue at the puncture site and reduce the likelihood of tissue tear. Insome embodiments, devices (e.g., sutures) and methods provided hereinreduce suture stress concentration at suture puncture points. In someembodiments, sutures with shaped cross-sectional profiles distributeforces more evenly (e.g., to the inner surface of the suture puncturehole) than traditional suture shapes/confirmation. In some embodiments,cross-sectionally-shaped sutures distribute tension about the suturepuncture points. In some embodiments, rather than presenting a sharppoint or line of suture to tissue, as is the case with traditionalsutures, the sutures described herein present a flat or gently roundedplane to the leading edge of tissue, thereby increasing the surface areaover which force can be distributed. In some embodiments, onecross-sectional dimension of the suture is greater than the orthogonalcross-sectional dimension (e.g., 1.1× greater, 1.2× greater, 1.3×greater, 1.4× greater, 1.5× greater, 1.6× greater, 1.7× greater, 1.8×greater, 1.9× greater, >2× greater, 2.0× greater, 2.1× greater, 2.2×greater, 2.3× greater, 2.4× greater, 2.5× greater, 2.6× greater, 2.7×greater, 2.8× greater, 2.9× greater, 3.0× greater, >3.0× greater, 3.1×greater, 3.2× greater, 3.3× greater, 3.4× greater, 3.5× greater, 3.6×greater, 3.7× greater, 3.8× greater, 3.9× greater, 4.0× greater, >4.0×greater . . . >5.0× greater . . . >6.0× greater . . . >7.0× greater . .. >8.0× greater . . . >9.0× greater . . . >10.0× greater). In someembodiments, sutures provided herein are flat or ellipsoidal on crosssection, forming a ribbon-like conformation. In some embodiments,sutures are provided that do not present a sharp leading edge to thetissue. In some embodiments, use of the sutures described herein reducesthe rates of surgical dehiscence in all tissues (e.g., hernia repairs,etc.). In some embodiments, sutures are provided with cross-sectionalprofiles that provide optimal levels of strength, flexibility,compliance, macroporosity, and/or durability while decreasing thelikelihood of suture pull-through. In some embodiments, sutures areprovided with sizes or shapes to enlarge the suture/tissue interface ofeach suture/tissue contact point, thereby distributing force over agreater area.

In some embodiments, sutures of the present disclosure provide variousimprovements over conventional sutures. In some embodiments, suturesprovide: reduced likelihood of suture pull-through, increased closurestrength, decreased number of stitches for a closure, more rapid healingtimes, and/or reduction in closure failure relative to a traditionalsuture. In some embodiments, relative improvements in suture performance(e.g., initial closure strength, rate of achieving tissue strength,final closure strength, rate of infection, etc.) are assessed in atissue test model, animal test model, simulated test model, in silicotesting, etc. In some embodiments, sutures of the present disclosureprovide increased initial closure strength (e.g., at least a 10%increase in initial closure strength(e.g., >10%, >25%, >50%, >75%, >2-fold, >3-fold, >4-fold, >5-fold, >10-fold,or more). As used herein, “initial closure strength” refers to thestrength of the closure (e.g., resistance to opening), prior tostrengthening of the closure by the healing or scarring processes. Insome embodiments, the increased initial closure strength is due tomechanical distribution of forces across a larger load-bearing surfacearea that reduces micromotion and susceptibility to pull through. Insome embodiments, sutures of the present disclosure provide increasedrate of achieving tissue strength (e.g., from healing of tissue acrossthe opening, from ingrowth of tissue into the integrative (porous)design of the suture, etc.). In some embodiments, sutures of the presentdisclosure provide at least a 10% increase in rate of achieving tissuestrength(e.g., >10%, >25%, >50%, >75%, >2-fold, >3-fold, >4-fold, >5-fold, >10-fold,or more). In some embodiments, increased rate of return of tissuestrength across the opening further increases load bearing surface area,thereby promoting tissue stability and decreased susceptibility to pullthrough. In some embodiments, sutures of the present disclosureestablish closure strength earlier in the healing process (e.g., due togreater initial closure strength and/or greater rate of achieving tissuestrength) when the closure is most susceptible to rupture (e.g., atleast a 10% reduction in time to establish closure strength (e.g., >10%reduction, >25% reduction, >50% reduction, >75% reduction, >2-foldreduction, >3-fold reduction, >4-fold reduction, >5-foldreduction, >10-fold reduction, or more)). In some embodiments, suturesof the present disclosure provide increased final closure strength(e.g., at least a 10% increase in final closure strength(e.g., >10%, >25%, >50%, >75%, >2-fold, >3-fold, >4-fold, >5-fold, >10-fold,or more). In some embodiments, the strength of fully healed closure iscreated not only by interface between the two apposed tissue surfaces,as is the case with conventional suture closures, but also along thetotal surface area of the integrated suture. In some embodiments, tissueintegration into the suture decreases the rate of suture abscessesand/or infections that otherwise occur with solid foreign materials ofthe same size (e.g., at least a 10% reduction in suture abscesses and/orinfection (e.g., >10% reduction, >25% reduction, >50% reduction, >75%reduction, >2-fold reduction, >3-fold reduction, >4-foldreduction, >5-fold reduction, >10-fold reduction, or more)). In someembodiments, sutures provide at least a 10% reduction(e.g., >10%, >20%, >30%, >40%, >50%, >60%, >70%, >80%, >90%, or more) insuture pull-through (e.g. through tissue (e.g., epidermal tissue,peritoneum, adipose tissue, cardiac tissue, or any other tissue in needof suturing), or through control substance (e.g., ballistic gel)).

In some embodiments, sutures are provided with any suitablecross-section profile or shape that provides reduced stress at thetissue puncture site, point of contact with tissue, and/or closure site.In some embodiments, sutures have cross-sectional dimensions (e.g.,width and/or depth) or between 0.1 mm and 1 cm (e.g., 0.1 mm . . . 0.2mm . . . 0.5 mm . . . 1.0 mm . . . 2.0 mm . . . 5.0 mm . . . 1 cm). Insome embodiments, the suture dimensions (e.g., width and/or depth) thatminimize pull-through and/or provide maximum load are utilized. In someembodiments, optimal suture dimensions are empirically determined for agiven tissue and suture material. In some embodiments, one or bothcross-sectional dimensions of a suture are the same as thecross-sectional dimensions of a traditional suture. In some embodiments,a suture comprises the same cross-sectional area as a traditionalsuture, but with different shape and/or dimensions. In some embodiments,a suture comprises the greater cross-sectional area than a traditionalsuture. In some embodiments, a suture cross-section provides a broadleading edge to spread pressure out over a broader portion of tissue. Insome embodiments, a suture cross-section provides a shaped leading edge(e.g., convex) that evenly distributes force along a segment of tissue,rather than focusing it at a single point. In some embodiments, shapedsutures prevent pull-through by distributing forces across the tissuerather than focusing them at a single point. In some embodiments,sutures prevent pull-through by providing a broader cross-section thatis more difficult to pull through tissue.

In some embodiments, ribbon-like suture or flat sutures are provided. Insome embodiments, sutures provided herein comprise any suitablecross-sectional shape that provides the desired qualities andcharacteristics. In some embodiments, suture cross-sectional shapeprovides enhanced and/or enlarged leading edge surface distance and/orarea (e.g. to reduce localized pressure on tissue). In some embodiments,suture cross-sectional shape comprises: an ellipse, half-ellipse,half-circle, gibbous, rectangle, square, crescent, pentagon, hexagon,concave ribbon, convex ribbon, H-beam, I-beam, dumbbell, etc. In someembodiments, a suture cross-sectional profile comprises any combinationof curves, lines, corners, bends, etc. to achieve a desired shape. Insome embodiments, the edge of the sutures configured to contact thetissue and/or place pressure against the tissue is broader than one ormore other suture dimensions. In some embodiments, the edge of thesutures configured to contact the tissue and/or place pressure againstthe tissue is shaped to evenly distribute forces across the region ofcontact.

In some embodiments, hollow core sutures are provided such as thatdepicted in FIG. 10. More specifically, FIG. 10 depicts a medical device10 that includes a surgical needle 12 and an elongated suture 14. InFIG. 10, the needle 12 includes a contoured or curved needle with aflattened cross-sectional profile, but needles with generally anygeometry could be used. The suture 14 can be a hollow core suture with afirst end 14 a attached to the needle 12 and a second end 14 b located adistance away from the needle 12. As shown, the entire length of thesuture 14 between the first and second ends 14 a, 14 b can include atubular wall 16 that defines a hollow core 18. In other versions,however, less than the entire length of the suture 14 can be tubular.For example, it is foreseeable that either or both of the first andsecond ends 14 a, 14 b can have a non-tubular portion or portion ofother geometry. Such non-tubular portions could be for attaching thefirst end 14 a of the suture 14 to the needle 12 or for tying off thesecond end 14 b, for example. In versions where the entire length of thesuture 14 is tubular, as shown, the entire length of the suture 14including the ends and central portion also has generally a constant oruniform diameter or thickness in the absence of stresses. That is, noportion of the suture 14 is meaningfully larger in diameter than anyother portion of the suture 14. Moreover, no aspect, end, or otherportion of the suture 14 is intended to be or is actually passedthrough, disposed in, received in, or otherwise positioned inside of thehollow core 18. The hollow core 18 is adapted for receiving tissuein-growth only.

In some embodiments, the tubular wall 16 can have a diameter in a rangeof approximately 1 mm to approximately 10 mm and can be constructed of amaterial such as, for example, polyethylene terephthalate, nylon,polyolefin, polypropylene, silk, polymers p-dioxanone, co-polymer ofp-dioxanone, ε-caprolactone, glycolide, L(−)-lactide, D(+)-lactide,meso-lactide, trimethylene carbonate, polydioxanone homopolymer, andcombinations thereof. So constructed, the tubular wall 16 of the suture14 can be radially deformable such that it adopts a firstcross-sectional profile in the absence of lateral stresses and a secondcross-sectional profile in the presence of lateral stresses. Forexample, in the absence of lateral stresses, the tubular wall 16 andtherefore the suture 14 depicted in FIG. 10, for example, can have acircular cross-sectional profile, thereby exhibiting radial symmetry. Inthe presence of a lateral stress, such a suture 14 could then exhibit apartially or wholly collapsed conformation.

In at least one version of the medical device 10, at least some of thetubular wall 16 can be macroporous defining a plurality of pores 20(e.g., openings, apertures, holes, etc.), only a few of which areexpressly identified by reference number and lead line in FIG. 10 forclarity. The pores 20 extend completely through the mesh wall 16 to thehollow core 18. In some versions, the tubular wall 16 can be constructedof a woven or knitted mesh material. In one version, the wall 16 can beconstructed of a knitted polypropylene mesh material similar oridentical to that which is available under the trade name Prolene SoftMesh and offered for sale by Ethicon. Other similarly constructed meshmaterials would be suitable as well.

As used herein, the term “macroporous” can include pore sizes that areat least greater than or equal to approximately 200 microns and,preferably, greater than or equal to 500 microns. In some versions ofthe medical device 10, the size of at least some the pores 20 in thesuture 14 can be in a range of approximately 500 microns toapproximately 4 millimeters. In another version, at least some of thepores 20 can have a pore size in the range of approximately 500 micronsto approximately 2.5 millimeters. In another version, at least some ofthe pores 20 can have a pore size in the range of approximately 1millimeter to approximately 2.5 millimeters. In another version, thesize of at least some of the pores 20 can be approximately 2millimeters. Moreover, in some versions, the pores 20 can vary in size.For example, as mentioned above and as also illustrated in FIG. 10A, insome versions, some of the pores 20 a can be macroporous (e.g., greaterthan approximately 200 microns) and some of the pores 20 b can bemicroporous (e.g., less than approximately 200 microns). The presence ofmicroporosity (i.e., pores less than approximately 200 microns) in suchversions of the disclosed suture may only be incidental to themanufacturing process, which can including knitting, weaving, extruding,blow molding, or otherwise, but not necessarily intended for any otherfunctional reason regarding biocompatibility or tissue integration. Thepresence of microporosity (i.e, some pores less than approximately 200microns in size) as a byproduct or incidental result of manufacturingdoes not change the character of the disclosed macroporous suture (e.g.,with pores greater than approximately 200 microns, and preferablygreater than approximately 500 microns, for example), which facilitatestissue in-growth to aid biocompatibility, reduce tissue inflammation,and decrease suture pull-through.

In versions of the disclosed suture that has both macroporosity andmicroporosity, the number of pores 20 that are macroporous can be in arange from approximately 1% of the pores to approximately 99% of thepores (when measured by pore cross-sectional area), in a range fromapproximately 5% of the pores to approximately 99% of the pores (whenmeasured by pore cross-sectional area), in a range from approximately10% of the pores to approximately 99% of the pores (when measured bypore cross-sectional area), in a range from approximately 20% of thepores to approximately 99% of the pores (when measured by porecross-sectional area), in a range from approximately 30% of the pores toapproximately 99% of the pores (when measured by pore cross-sectionalarea), in a range from approximately 50% of the pores to approximately99% of the pores (when measured by pore cross-sectional area), in arange from approximately 60% of the pores to approximately 99% of thepores (when measured by pore cross-sectional area), in a range fromapproximately 70% of the pores to approximately 99% of the pores (whenmeasured by pore cross-sectional area), in a range from approximately80% of the pores to approximately 99% of the pores (when measured bypore cross-sectional area), or in a range from approximately 90% of thepores to approximately 99% of the pores (when measured by porecross-sectional area).

So configured, the pores 20 in the suture 14 are arranged and configuredsuch that the suture 14 is adapted to facilitate and allow tissuein-growth and integration through the pores 20 in the mesh wall 16 andinto the hollow core 18 when introduced into a body. That is, the pores20 are of sufficient size to achieve maximum biocompatibility bypromoting neovascularization and local/normal tissue in-growth throughthe pores 20 and into the hollow core 18 of the suture 14. As such,tissue growth through the pores 16 and into the hollow core 20 enablesthe suture 14 and resultant tissue to combine and cooperatively increasethe strength and efficacy of the medical device 10, while alsodecreasing irritation, inflammation, local tissue necrosis, andlikelihood of pull through. Instead, the suture 14 promotes theproduction of healthy new tissue throughout the suture constructincluding inside the pores 20 and the hollow core 18.

While the suture 14 in FIG. 10 has been described as including a singleelongated hollow core 18, in some embodiments, a suture according to thepresent disclosure can comprise a tubular wall defining a hollow coreincluding one or more interior voids (e.g., extending the length of thesuture). In some versions, at least some of the interior voids can havea size or diameter > approximately 200 microns, > approximately 300microns, > approximately 400 microns, > approximately 500 microns, >approximately 600 microns, > approximately 700 microns, > approximately800 microns, > approximately 900 microns, > approximately 1 millimeter,or > approximately 2 millimeters. In some embodiments, a sutureaccording to the present disclosure can comprise a tubular wall defininga hollow core including one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, ormore) lumens (e.g., running the length of the suture). In someembodiments, a suture according to the present disclosure can comprise atubular wall defining a hollow core including a honeycomb structure, a3D lattice structure, or other suitable interior matrix, which definesone or more interior voids. In some versions, at least some of theinterior voids in the honeycomb structure, 3D lattice structure, orother suitable matrix can have a size or diameter > approximately 200microns, > approximately 300 microns, > approximately 400 microns, >approximately 500 microns, > approximately 600 microns, > approximately700 microns, > approximately 800 microns, > approximately 900 microns, >approximately 1 millimeter, or > approximately 2 millimeters. In someembodiments, a void comprises a hollow core. In some embodiments, ahollow core can include a hollow cylindrical space in the tubular wall,but as described, the term “hollow core” is not limited to defining acylindrical space, but rather could include a labyrinth of interiorvoids defined by a honeycomb structure, a 3D lattice structure, or someother suitable matrix. In some embodiments, sutures comprise a hollow,flexible structure that has a circular cross-sectional profile in itsnon-stressed state, but which collapses into a more flattenedcross-sectional shape when pulled in an off-axis direction. In someembodiments, sutures are provided that exhibit radial symmetry in anon-stressed state. In some embodiments, radial symmetry in anon-stressed state eliminates the need for directional orientation whilesuturing. In some embodiments, sutures are provided that exhibit aflattened cross-sectional profile when off-axis (longitudinal axis)force is applied (e.g., tightening of the suture against tissue) (SEEFIG. 14), thereby more evenly distributing the force applied by thesuture on the tissue. In some embodiments, sutures are provided thatexhibit a flattened cross-sectional profile when axial force is applied.In some embodiments, sutures comprise flexible structure that adopts afirst cross-sectional profile in its non-stressed state (e.g., suturingprofile), but adopts a second cross-sectional shape when pulled in anoff-axis direction (e.g., tightened profile). In some embodiments, asuture is hollow and/or comprises one or more internal voids (e.g., thatrun the length of the suture). In some embodiments, internal voids areconfigured to encourage the suture to adopt a preferred conformation(e.g., broadened leading edge to displace pressures across the contactedtissue) when in a stressed states (e.g., tightened profile). In someembodiments, internal voids are configured to allow a suture to adoptradial exterior symmetry (e.g., circular outer cross-sectional profile)when in a non-stressed state. In some embodiments, varying the size,shape, and/or placement of internal voids alters one or both of thefirst cross-sectional profile (e.g., non-stressed profile, suturingprofile) and second cross-sectional profile (e.g., off-axis profile,stressed profile, tightened profile).

Sutures, which are substantially linear in geometry, have two distinctends, as described above with reference to FIG. 10, for example. In someembodiments, both ends are identical. In some embodiments, each end isdifferent. In some embodiments, one or both ends are structurallyunadorned. In some embodiments, one or more ends is attached to or atleast configured for attachment to a needle via swaging, sonic welding,adhesive, tying, or some other means (as shown FIG. 10). In someembodiments, the second end 14 b of the suture 14 is configured toinclude an anchor 22 (e.g., FIGS. 11, 12, 13) for anchoring the suture14 against the tissue through which the suture 14 is inserted. In someembodiments, the second end 14 b of the suture 14 is configured toanchor the suture at the beginning of the closure. In some embodiments,the second end 14 b of the suture 14 includes an anchor 22 that is astructure that prevents the suture 14 from being pulled completelythrough the tissue. In some embodiments, the anchor 22 has a greaterdimension than the rest of the suture 14 (at least 10% greater, at least25% greater, at least 50% greater, at least 2-fold greater, at least3-fold greater, at least 4-fold greater, at least 5-fold greater, atleast 6-fold greater, at least 10-fold greater, etc.). In someembodiments, the anchor 22 comprises a structure with any suitable shapefor preventing the suture 14 from being pulled through the hole (e.g.,ball, disc, plate, cylinder), thereby preventing the suture 14 frombeing pulled through the insertion hole. In some embodiments, the anchor22 of the suture 14 comprises a closed loop, as depicted in FIG. 11, forexample. In some embodiments, the closed loop is of any suitablestructure including, but not limited to a crimpled loop (FIG. 11),flattened loop (FIG. 12), or a formed loop (FIG. 13). In someembodiments, a loop can be integrated into the end of the suture 14. Insome embodiments, a separate loop structure can be attached to thesuture 14. In some embodiments, the needle 12 can be passed through theclosed loop anchor 22 to create a cinch for anchoring the suture 14 tothat point. In some embodiments, the anchor 22 can comprise one or morestructures (e.g., barb, hook, etc.) to hold the end of the suture 14 inplace. In some embodiments, one or more anchor 22 structures (e.g.,barb, hook, etc.) are used in conjunction with a closed loop to ratchetdown the cinch and hold its position. In some embodiments, a knotlessanchoring system can be provided.

In some embodiments, and as briefly mentioned relative to FIG. 10, thepresent disclosure provides suturing needles with cross-sectionalprofiles configured to prevent suture pull-through and methods of usethereof. In some embodiments, suturing needles are provided comprisingcross-section shapes (e.g. flat, elliptical, transitioning over thelength of the needle, etc.) that reduce tension against the tissue atthe puncture site and reduce the likelihood of tissue tear. In someembodiments, one cross-sectional dimension of the needle is greater thanthe orthogonal cross-sectional dimension (e.g., 1.1× greater, 1.2×greater, 1.3× greater, 1.4× greater, 1.5× greater, 1.6× greater, 1.7×greater, 1.8× greater, 1.9× greater, >2× greater, 2.0× greater, 2.1×greater, 2.2× greater, 2.3× greater, 2.4× greater, 2.5× greater, 2.6×greater, 2.7× greater, 2.8× greater, 2.9× greater, 3.0× greater, >3.0×greater, 3.1× greater, 3.2× greater, 3.3× greater, 3.4× greater, 3.5×greater, 3.6× greater, 3.7× greater, 3.8× greater, 3.9× greater, 4.0×greater, >4.0× greater . . . >5.0× greater . . . >6.0× greater . .. >7.0× greater . . . >8.0× greater . . . >9.0× greater . . . >10.0×greater). In some embodiments, suturing needles are provided circular inshape at its point (e.g., distal end), but transition to a flattenedprofile (e.g., ribbon-like) to the rear (e.g. proximal end). In someembodiments, the face of the flattened area is orthogonal to the radiusof curvature of the needle. In some embodiments, suturing needles createa slit (or flat puncture) in the tissue as it is passed through, ratherthan a circle or point puncture. In some embodiments, suturing needlesare provided circular in shape at its point (e.g., distal end), buttransition to a 2D cross-sectional profile (e.g., ellipse, crescent,half moon, gibbous, etc.) to the rear (e.g. proximal end). In someembodiments, suturing needles provided herein find use with the suturesdescribed herein. In some embodiments, suturing needles find use withsutures of the same shape and/or size. In some embodiments, suturingneedles and sutures are not of the same size and/or shape. In someembodiments, suturing needles provided herein find use with traditionalsutures. Various types of suture needles are well known in the art. Insome embodiments, suturing needles provided herein comprise any suitablecharacteristics of suturing needles known to the field, but modifiedwith dimensions described herein.

In some embodiments, the present disclosure also provides compositions,methods, and devices for anchoring the suture at the end of the closure(e.g., without tying the suture to itself). In some embodiments, one ormore securing elements (e.g., staples) are positioned over the terminalend of the suture to secure the end of the closure. In some embodiments,one or more securing elements (e.g., staples) are secured to the last“rung” of the suture closure (e.g., to hold the suture tight across theclosure. In some embodiments, a securing element is a staple. In someembodiments, a staple comprises stainless steel or any other suitablematerial. In some embodiments, a staple comprises a plurality of pinsthat can pass full thickness through 2 layers of suture. In someembodiments, staple pins are configured to secure the suture end withoutcutting and/or weakening the suture filament. In some embodiments, astaple forms a strong joint with the suture. In some embodiments, astaple is delivered after the needle is cut from the suture. In someembodiments, a staple is delivered and the needle removed simultaneously

In some embodiments, the present disclosure provides devices (e.g.,staple guns) for delivery of a staple into tissue to secure the sutureend. In some embodiments, a staple deployment device simultaneously ornear-simultaneously delivers a staple and removes the needle from thesuture. In some embodiments, a staple deployment device comprises abottom lip or shelf to pass under the last rung of suture (e.g., betweenthe suture and tissue surface) against which the pins of the staple canbe deformed into their locked position. In some embodiments, the bottomlip of the staple deployment device is placed under the last rung ofsuture, the free tail of the suture is placed within the staplingmechanism, and the suture is pulled tight. In some embodiments, whileholding tension, the staple deployment device is activated, therebyjoining the two layers of suture together. In some embodiments, thedevice also cuts off the excess length of the free suture tail. In someembodiments, the staple deployment device completes the running sutureand trims the excess suture in one step. In some embodiments, a sutureis secured without the need for knot tying. In some embodiments, only 1staple is needed per closure. In some embodiments, a standard stapler isused to apply staples and secure the suture end. In some embodiments, astaple is applied to the suture end manually.

In some embodiments, sutures provided herein provide tissue integrativeproperties to increase the overall strength of the repair (e.g., at anearlier time-point than traditional sutures). In some embodiments,sutures are provided with enhanced tissue adhesion properties. In someembodiments sutures are provided that integrate with the surroundingtissue. In some embodiments, tissue integrative properties find use inconjunction with any other suture characteristics described herein. Insome embodiments, sutures allow integration of healing tissue into thesuture. In some embodiments, tissue growth into the suture is promoted(e.g., by the surface texture of the suture). In some embodiments,tissue growth into the suture prevents sliding of tissue around suture,and/or minimizes micromotion between suture and tissue. In someembodiments, tissue in-growth into the suture increases the overallstrength of the repair by multiplying the surface area for scar inestablishing continuity between tissues. Conventionally, the strength ofa repair is dependent only on the interface between the two tissuesurfaces being approximated. In some embodiments in-growth of tissueinto the suture adds to the surface area of the repair, therebyenhancing its strength. In some embodiments, increasing the surface areafor scar formation, the closure reaches significant strength morequickly, narrowing the window of significant risk of dehiscence.

In some embodiments, the surface and/or internal texture of a suturepromote tissue adhesion and/or ingrowth. In some embodiments, asdiscussed above specifically with reference to FIG. 10, a suture of thepresent disclosure can comprise a porous (e.g., macroporous) and/ortextured material. In some embodiments, a suture comprises a porous(e.g., macroporous) and/or textured exterior. In some embodiments, poresin the suture allow tissue in-growth and/or integration. In someembodiments, a suture comprises a porous ribbon-like structure, insteadof a tubular like structure. In some embodiments, a porous suturecomprises a 2D cross-sectional profile (e.g., elliptical, circular(e.g., collapsible circle), half moon, crescent, concave ribbon, etc.).In some embodiments, a porous suture comprises polypropylene or anyother suitable suture material. In some embodiments, pores are between500 μm and 3.5 mm or greater in diameter (e.g., e.g., >500 μm indiameter (e.g., >500 μm, >600 μm, >700 μm 800 μm, >900 μm, >1 mm, ormore). In some embodiments pores are of varying sizes. In someembodiments, a suture comprises any surface texture suitable to promotetissue in-growth and/or adhesion. In some embodiments, suitable surfacetextures include, but are not limited to ribbing, webbing, mesh,grooves, etc. In some embodiments, the suture may include filaments orother structures (e.g., to provide increased surface area and/orincreased stability of suture within tissue). In some embodiments,interconnected porous architecture is provided, in which pore size,porosity, pore shape and/or pore alignment facilitates tissue in-growth.

In some embodiments, a suture comprises a mesh and/or mesh-likeexterior. In some embodiments, a mesh exterior provides a flexiblesuture that spreads pressure across the closure site, and allows forsignificant tissue in-growth. In some embodiments, the density of themesh is tailored to obtain desired flexibility, elasticity, andin-growth characteristics.

In some embodiments, a suture is coated and/or embedded with materialsto promote tissue ingrowth. Examples of biologically active compoundsthat may be used sutures to promote tissue ingrowth include, but are notlimited to, cell attachment mediators, such as the peptide containingvariations of the “RGD” integrin binding sequence known to affectcellular attachment, biologically active ligands, and substances thatenhance or exclude particular varieties of cellular or tissue ingrowth.Such substances include, for example, osteoinductive substances, such asbone morphogenic proteins (BMP), epidermal growth factor (EGF),fibroblast growth factor (FGF), platelet-derived growth factor (PDGF),insulin-like growth factor (IGF-I and II), TGF-β, etc. Examples ofpharmaceutically active compounds that may be used sutures to promotetissue ingrowth include, but are not limited to, acyclovir, cephradine,malfalen, procaine, ephedrine, adriomycin, daunomycin, plumbagin,atropine, guanine, digoxin, quinidine, biologically active peptides,chlorin e.sub.6, cephalothin, proline and proline analogues such ascis-hydroxy-L-proline, penicillin V, aspirin, ibuprofen, steroids,nicotinic acid, chemodeoxycholic acid, chlorambucil, and the like.Therapeutically effective dosages may be determined by either in vitroor in vivo methods.

Sutures are well known medical devices in the art. In some embodiments,sutures have braided or monofilament constructions. In some embodimentssutures are provided in single-armed or double-armed configurations witha surgical needle mounted to one or both ends of the suture, or may beprovided without surgical needles mounted. In some embodiments, the endof the suture distal to the needle comprises one or more structures toanchor the suture. In some embodiments, the distal end of the suturecomprises one or more of a: closed loop, open loop, anchor point, barb,hook, etc. In some embodiments, sutures comprise one or morebiocompatible materials. In some embodiments, sutures comprise one ormore of a variety of known bioabsorbable and nonabsorbable materials.For example, in some embodiments, sutures comprise one or more aromaticpolyesters such as polyethylene terephthalate, nylons such as nylon 6and nylon 66, polyolefins such as polypropylene, silk, and othernonabsorbable polymers. In some embodiments, sutures comprise one ormore polymers and/or copolymers of p-dioxanone (also known as1,4-dioxane-2-one), ε-caprolactone, glycolide, L(−)-lactide,D(+)-lactide, meso-lactide, trimethylene carbonate, and combinationsthereof. In some embodiments, sutures comprise polydioxanonehomopolymer. The above listing of suture materials should not be viewedas limiting. Suture materials and characteristics are known in the art.Any suitable suture materials or combinations thereof are within thescope of the present disclosure. In some embodiments, sutures comprisesterile, medical grade, surgical grade, and or biodegradable materials.In some embodiments, a suture is coated with, contains, and/or elutesone or more bioactive substances (e.g., antiseptic, antibiotic,anesthetic, promoter of healing, etc.).

In some embodiments, the structure and material of the suture providesphysiologically-tuned elasticity. In some embodiments, a suture ofappropriate elasticity is selected for a tissue. In some embodiments,suture elasticity is matched to a tissue. For example, in someembodiments, sutures for use in abdominal wall closure will have similarelasticity to the abdominal wall, so as to reversibly deform along withthe abdominal wall, rather than act as a relatively rigid structure thatwould carry higher risk of pull-through. In some embodiments, elasticitywould not be so great however, so as to form a loose closure that couldeasily be pulled apart. In some embodiments, deformation of the suturewould start occurring just before the elastic limit of its surroundingtissue, e.g., before the tissue starts tearing or irreversiblydeforming.

In some embodiments, sutures described herein provide a suitablereplacement or alternative for surgical repair meshes (e.g., those usedin hernia repair). In some embodiments, the use of sutures in place ofmesh reduces the amount of foreign material placed into a subject (e.g.,50 cm² (suture) v. 240 cm² (mesh)). In some embodiments, the decreasedlikelihood of suture pull-through allows the use of sutures to closetissues not possible with traditional sutures (e.g., areas of poortissue quality (e.g., friable or weak tissue) due to conditions likeinflammation, fibrosis, atrophy, denervation, congenital disorders,attenuation due to age, or other acute and chronic diseases). Like asurgical mesh, sutures described herein permit a distribution of forcesover a larger area thereby delocalizing forces felt by the tissue andreducing the chance of suture pull-though and failure of the closure.

In some embodiments, sutures are permanent, removable, or absorbable. Insome embodiments, permanent sutures provide added strength to a closureor other region of the body, without the expectation that the sutureswill be removed upon the tissue obtaining sufficient strength. In suchembodiments, materials are selected that pose little risk of long-termresidency in a tissue or body. In some embodiments, removable suturesare stable (e.g., do not readily degrade in a physiologicalenvironment), and are intended for removal when the surrounding tissuereaches full closure strength. In some embodiments, absorbable suturesintegrate with the tissue in the same manner as permanent or removablesutures, but eventually (e.g., >1 week, >2 weeks, >3 weeks, >4weeks, >10 weeks, >25 weeks, >1 year) biodegrade and/or are absorbedinto the tissue after having served the utility of holding the tissuetogether during the post-operative and/or healing period. In someembodiments absorbable sutures present a reduced foreign body risk.

Although prevention of dehiscence of abdominal closures (e.g., herniaformation) is specifically described at an application of embodiments ofthe present disclosure, the sutures described herein are useful forjoining any tissue types throughout the body. In some embodiments,sutures described herein are of particular utility to closures that aresubject top tension and/or for which cheesewiring is a concern.Exemplary tissues within which the present disclosure finds use include,but are not limited to: connective tissue, muscle, dermal tissue,cartilage, tendon, or any other soft tissues. Specific applications ofsutures described herein include placation, suspensions, slings, etc.Sutures described herein find use in surgical procedures, non-surgicalmedical procedures, veterinary procedures, in-field medical procedures,etc. The scope of the present disclosure is not limited by the potentialapplications of the sutures described herein.

Yet, from the foregoing, it should also be appreciated that the presentdisclosure additionally provides both a novel method of re-apposing softtissue and a novel method of manufacturing a medical device.

Based on the present disclosure, a method of re-apposing soft tissue canfirst include piercing a portion of the soft tissue with the surgicalneedle 12 (as shown in FIG. 10, for example) attached to a first end 14a of a tubular suture 14. Next, a physician can thread the tubularsuture 14 through the soft tissue and make one or more stitches, as isgenerally known. Finally, the physician can anchor the tubular suture 14in place in the soft tissue. As disclosed hereinabove, the tubularsuture 14 comprises a tubular mesh wall 16 defining a hollow core 18.The tubular mesh wall 16 defines a plurality or pores 20, each with apore size that is greater than or equal to approximately 500 microns. Soconfigured, the tubular suture 14 is adapted to accommodate the softtissue growing through the tubular mesh wall 16 and into the hollow core18, thereby integrating with the suture. In some versions, the methodcan further and finally include anchoring the tubular suture 14 in placeby passing the surgical needle 12 through a closed loop anchor 22 (asseen in FIG. 11, for example) at the second end 14 b of the tubularsuture 14 and creating a cinch for anchoring the suture 14 to the softtissue. Once anchored, the suture 14 can be cut off near the anchor 22and any remaining unused portion of the suture 14 can be discarded.

A method of manufacturing a medical device in accordance with thepresent disclosure can include forming a tubular wall 16 having aplurality or pores 20 and defining a hollow core 18, each pore 20 havinga pore size that is greater than or equal to approximately 500 microns.Additionally, the method of manufacturing can include attaching a firstend 14 a of the tubular wall 14 to a surgical needle 12, such as thatillustrated in FIG. 10. Forming the tubular wall 14 can include forminga tube from a mesh material. The tubular mesh wall 16 may be formed bydirectly weaving or knitting fibers into a tube shape. Alternatively,forming the tubular mesh wall 16 can include weaving or knitting fibersinto a planar sheet and subsequently forming the planar sheet into atube shape. Of course, other manufacturing possibilities exist andknitting and weaving fibers are not the only possibilities for creatinga porous tube within the scope of the present disclosure, but rather,are mere examples.

Still further, a method of manufacturing a medical device 10 inaccordance with the present disclosure can include providing an anchor22 on an end of the tubular wall 16 opposite the needle 12. In someversions of the method, and as one example only, providing the anchorcan be as simple as forming a loop, such as to resemble the anchor 22depicted in FIG. 11.

To substantiate some characteristics of the medical device 10 describedherein, a number of experiments were conducted and the character andresults of some of those experiments are presented below.

EXPERIMENTAL WORK Example 1 Finite Element Analyses of the Suture/TissueInterface for Sutured Abdominal Wall Closures

Experiments were conducted during development of embodiments of thepresent disclosure to perform finite element analyses of thesuture/tissue interface for sutured abdominal wall closures. A theoreticbasis was created for intuitive concepts and clinical observations asthe first step in the design of this line of inquiry (See FIGS. 1,2).Finite element analysis of the suture/tissue interface was performed(FIG. 3). Experiments demonstrated that increasing suture size (i.e.,diameter) decreases the forces at the suture/tissue interface ashypothesized (FIG. 4). Suture shape was also shown to impact the localforces applied on the tissue by suture (FIG. 5).

Example 2

Creating “equivalency” between conventional and macroporous suture ofthe present disclosure.

A size O-polypropylene suture is commonly used in hernia repair for itsfeatures of handling and high strength. Experiments were conducted todetermine a cross-sectionally shaped suture that is the relativeequivalent to such a suture. The two-dimensional suture was compared tothis commonly used standard suture for load at yield, maximal load, andYoung's modulus. An Instron 5964 was used for mechanical testing.Experiments demonstrated a relative equivalency between O-polypropyleneand a two-dimensional ribbon suture of 5 mm in width (FIGS. 6 and 7). A5-0 polypropylene suture, used in experimental rat hernia repair, had anequivalency to a 2 mm wide sample of a macroporous suture of the presentdisclosure.

Example 3 Creating and Validating an Acute Suture Pull-Through ModelUsing Biologic Tissue and Tensometry

Porcine linea alba is available from local slaughterhouses to providerealistic testing of acute suture pull-through. Standard suture andmacroporous suture of the present disclosure were placed uniformlythrough porcine tissue. To decrease biologic variability, adjacentpieces of fascia were randomized to either standard suture ortwo-dimensional suture, with the width of the suture bite mimicking whatis done clinically (1 cm from the edge). Tensometry using an Instron5964 testing suture pull-through at both slow and fast speeds tosimulate both baseline suture tension and episodic high tension (e.g.,coughing, stairs, etc.) were performed. Considering biologic variabilityand the readily accessible biologic materials, a suitable number oftests were performed for both standard and macroporous suture of thepresent disclosure.

Example 4 Rat Hernia Model

Experiments were conducted during development of embodiments of thepresent disclosure reproducing an established rat hernia model to inorder to assess pull-through of standard suture and our experimentalmacroporous suture.

A well-established rat hernia model was reproduced (Dubay D A, Ann Surg2007; 245: 140-146; herein incorporated by reference in its entirety).Rat ventral hernias were randomized to repair with two standard sutures(5-0 polypropylene), and with two integrated sutures with equivalenttensile strength. One month after hernia repair, the rats weresacrificed and analyzed for hernia recurrence, hernia size, and suturepull-through. Histology of the abdominal wall for analysis of sutureintegration was assessed by blinded observers. In these experiments,none of the macroporous sutures of the present disclosure pulled throughin 17 rat hernias (i.e., 34 of 34 integrated macroporous suturesmaintained their hold on the abdominal wall without failure, with theimage on the left-hand side of FIG. 17 as a typical example). Themacroporous suture of the present disclosure facilitated tissueintegration for every suture of every rat in which it was used. On theleft of FIG. 18, in one instance there is an 82% reduction in the defectarea one month after repair with macroporous suture. In contrast, in 13rat hernias repaired with a conventional suture, 11 of 13 rats had atleast one suture completely pull-through the abdominal wall. Theright-hand side of FIG. 17 is an example of a hernia repair failure withboth sutures pulling through. On the right-hand side of FIG. 18, it isshown that hernia size increased 42% one month after repair withstandard suture in one test animal. FIG. 19 shows a graph comparing themean defect area of 30 rat hernias repaired according to FIGS. 17 and 18randomized to repair either with the macroporous suture of the presentdisclosure or with a conventional suture. One month after repair,average hernia size decreased 54% with the experimental macroporoussuture of the present disclosure, while hernia size increased 5% withthe conventional suture. Some element of recurrent hernia with bothstandard and experimental sutures was expected—only two sutures wereused in this model, while 6 would be required to achieve a completelyclosed abdominal wall.

Example 5 Suture Width

Experiments conducted to evaluate the effect of suture widthdemonstrated that increased suture width resulted in an increase inmaximum load of the suture, resulting in decreased pull-through of thesuture. Tinned copper flat braided wire was used as a prototype forsuture of varying widths. Relative to tissue, metal wire is essentiallynoncompliant, creating a system that isolates the effect of the variableof width on pull-through of suture placed in tissue. Wires of varyingwidth were placed into two different substances: fresh animal tissue(porcine abdominal wall) and synthetic foam sheeting, and an Instron5942 tensometer was used to precisely measure the breaking strength ofthis system. Wire was tested from widths of 0.36 mm (equivalent to Oprolene suture) to 5 mm. These experiments was to examined the effectsof increasing suture width in both animal tissue and synthetic “tissue”to determine if there were any differences between an ex vivo andsynthetic substrate.

FIG. 15 demonstrates that with increasing suture width greater force isrequired to pull-through porcine abdomen. Unexpectedly, the benefits ofincreasing suture width began peaking at a width of around 3 mm. At awidth of 3.75 mm, pull-through resistance (maximum load of the system)actually decreased; video time lapse analysis shows that at this widthtissue began fracturing on both sides of wire, tending to come off as asegment of tissue. In contrast, at smaller widths, wire would cutthrough tissue in a single fracture line. Fracture pattern therefore hasa bearing on the maximum strength of the system.

FIG. 16 demonstrates that the same relationship is preserved insynthetic tissue. In this so-called “clean” system, utilizing foaminstead of animal tissue (foam being a homogenous substance with fewermechanical variables than animal tissue), benefits of wider thanconventional suture were demonstrated, further confirming that increasedload-bearing surface area at the suture-tissue interface decreasespull-through. However, in a similar manner to porcine tissue, thebenefit of increasing width was demonstrated up to 3.75 mm, at whichpoint the foam substrate began fracturing as a segment.

While it was initially hypothesized that the wider the suture the lessit will tear through, in some embodiments, suture width is not the onlyconsideration. For example, it is clear that tissue integration (i.e.,in-growth through the suture 14 pores 20 and into the hollow core 28)into the suture 14 further increases the strength of the repair andreduces and/or completely eliminates the risk of suture pull-through.Moreover, as shown above, experiments conducted during development ofvarious embodiments of the present disclosure demonstrate thatincreasing the load-bearing surface area will further reduce theoccurrence of pull through. Wire pulling experiments in porcine abdomen,confirmed such findings. In some experiments, with widths above 3.75 mm,pull-through resistance reduced. Rather than the suture tearing throughthe tissue in a straight line, it started breaking off the tissue as asegment or block. This finding was unexpected. These experiments wererepeated using a homogenous/synthetic substance to test whether thebenefit of increasing width would also peak. A rubber foam which wasabout the same thickness as porcine linea alba was used. Unexpectedly,the force required to pull the suture through the foam peaked at thesame suture width, and the foam even tore in the same pattern as theporcine tissue. The suture width to max load relationship was preservedin both animal and synthetic tissue.

Both these experiments indicate that the suture width/max loadrelationship is due to mechanical phenomena; although, the presentdisclosure is not limited to any particular mechanism of action and anunderstanding of the mechanism of action is not necessary to practicethe present disclosure.

Various modifications and variations of the described method and systemof the disclosure will be apparent to those skilled in the art withoutdeparting from the scope and spirit of the disclosure. Although thedisclosure has been described in connection with specific preferredembodiments, it should be understood that the disclosure as claimedshould not be unduly limited to such specific embodiments. Indeed,various modifications of the described modes for carrying out thedisclosure that are obvious to those skilled in the relevant fields areintended to be within the scope of the present disclosure.

We claim:
 1. A medical device comprising: a surgical needle; and anelongated mesh suture having a first end and a second end located awayfrom the first end, wherein the first end is selected from the groupconsisting of (a) an end directly attached to the surgical needle, (b) afree end, and (c) an end having a loop; the elongated suture including atubular wall, a hollow core inside of the tubular wall, and a pluralityof pores extending through the tubular wall, at least some of the poreshaving a pore size that is greater than or equal to approximately 500microns such that the pores are adapted to facilitate tissue integrationthrough the tubular wall of the suture when introduced into a body,wherein the suture is uniform in diameter along substantially its entirelength and the diameter is in a range of approximately 1 mm toapproximately 5 mm.
 2. The medical device of claim 1, wherein thetubular wall of the suture extends along the entirety of the suturebetween the first and second ends.
 3. The medical device of claim 1,wherein the pore size is in a range of approximately 500 microns toapproximately 4 millimeters.
 4. The medical device of claim 1, whereinthe pore size is in the range of approximately 500 microns toapproximately 2.5 millimeters.
 5. The medical device of claim 1 whereinthe pore size is in the range of approximately 1 millimeter toapproximately 2.5 millimeters.
 6. The medical device of claim 1, whereinthe pore size is approximately 2 millimeters.
 7. The medical device ofclaim 1, wherein the plurality of pores vary in pore size.
 8. Themedical device of claim 1, wherein the suture is constructed of amaterial selected from the group consisting of: polyethyleneterephthalate, nylon, polyolefin, polypropylene, silk, polymersp-dioxanone, co-polymer of p-dioxanone, ε-caprolactone, glycolide,L(−)-lactide, D(+)-lactide, meso-lactide, trimethylene carbonate,polydioxanone homopolymer, and combinations thereof.
 9. The medicaldevice of claim 1, wherein the suture is radially deformable such thatthe suture adopts a first cross-sectional profile in the absence oflateral stress and a second cross-sectional profile in the presence oflateral stress.
 10. The medical device of claim 9, wherein the firstcross-sectional profile exhibits radial symmetry.
 11. The medical deviceof claim 10, wherein the second cross-sectional profile exhibitspartially or wholly collapsed conformation.
 12. The medical device ofclaim 1, wherein the suture has a circular cross-sectional profile whenin a non-stressed state.
 13. The medical device of claim 1, furthercomprising an anchor attached to the second end of the suture forpreventing suture pull through during use, the anchor having a dimensionthat is larger than a diameter of the suture.
 14. The medical device ofclaim 13, wherein the anchor comprises a loop, a ball, a disc, acylinder, a barb, and/or a hook.
 15. The medical device of claim 1,wherein the tubular wall comprises a woven or knitted mesh material. 16.The medical device of claim 1, wherein the hollow core is a hollowcylindrical space.
 17. The medical device of claim 1, wherein the hollowcore includes a honeycomb structure, a 3D lattice structure, or othersuitable matrices defining one or more interior voids.
 18. The medicaldevice of claim 1, wherein the second end of the elongated mesh sutureis not connected to a needle.
 19. The medical device of claim 1, whereinthe second end of the elongated mesh suture is one of (a) a free end,(b) an end connected to an anchor, (c) an end having a loop, (d) an endconnected to a barb, or (e) an end connected to another surgical needle.20. A method of re-apposing soft tissue, the method comprising: piercinga portion of the soft tissue with a surgical needle; and threading anelongated mesh suture through the soft tissue, the elongated mesh suturehaving a first end and a second end located away from the first end,wherein the first end is selected from the group consisting of (a) anend directly attached to the surgical needle, (b) a free end, and (c) anend having a loop, wherein the tubular elongated mesh suture furthercomprises a tubular wall, a hollow core inside of the tubular wall, anda plurality of pores extending through the tubular wall, at least someof the pores having a pore size that is greater than or equal toapproximately 500 microns such that the tubular suture is adapted toaccommodate the soft tissue growing through the tubular mesh wall andinto the hollow core, thereby integrating with the suture, the elongatedmesh suture further being uniform in diameter along substantially itsentire length and with a diameter in a range of approximately 1 mm toapproximately 5 mm.
 21. The method of claim 20, wherein threading thetubular suture through the soft tissue comprises making a plurality ofstitches.
 22. The method of claim 20, further comprising anchoring thetubular suture in place in the soft tissue after threading the tubularsuture through the soft tissue.
 23. The method of claim 22, whereinanchoring the tubular suture in place comprises passing the surgicalneedle through a closed loop anchor at the second end of the tubularsuture and creating a cinch for anchoring the suture to the soft tissue.24. The method of claim 20, wherein a second end of the tubular meshsuture, which is opposite from the first end, is not connected to aneedle.
 25. The method of claim 20, wherein a second end of the tubularmesh suture is one of (a) a free end, (b) an end connected to an anchor,(c) an end having a loop, (d) an end connected to a barb, or (e) an endconnected to another surgical needle.